Electrical Upgrades on my 08 Altima Hybrid, possible?

[WJHybrid]

Let me start out by saying hello to everyone, as I am new to this site. I've done a lot of searching and just can't nail down an answer to what I am trying to do. I own a 2008 Nissan Altima Hybrid. I currently have the following installed in it -

Pioneer AVH-P4400BH Head Unit

All stock speakers have been changed to Infinity Kappas (dash, doors, and deck)

2 Alpine Type R (SWR-12D2) 12 inch Subwoofers

2 Memphis PR1.1000 Amplifiers (1000w RMS)

Power Acoustik 300w RMS Amplifier on my door and deck speakers, dash speakers powered by HU

Swapped standard 12v battery to a HC2000 Kinetik battery.

My hybrid car does not have a alternator, instead it powers accessories and charges the 12v battery by getting it's power from a DC-DC Converter. The Converter takes power from the Hybrid battery, converts it and sends it to the 12v system. I cannot find any exact amp rating that the DC Converter is putting out, but did locate a 120A fuse under my hood.

I originally installed all of the above using the stock battery and my voltage was going from 14.4v to 12.5v on big bass hits. After upgrading to the HC2000 Kinetik battery, voltage goes from 14.4v to 13.5v. Is this good, bad, acceptable, alarming? What is your opinion on it? I can say my headlights dimmed with the stock battery, with the HC2000, no longer happens.

I would like to actually at least feel I have the options of adding more subs/amps in the future and thus, this is where my dilemma starts. Since I do not have a traditional alternator, can't get a bigger one. I can't find any information online regarding upgrading the DC-DC Converter for higher output, don't even know if that is possible. Is performing the big 3 even possible on the Hybrid? Really hope someone who knows much more than me can shed some light on this situation. Thanks for any help anyone can provide.

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[marc2112 10+ year member]

Well if you got from 12.5 to 13.5 it's an improvement. You can't go crazy with amps and subs without an alt. Try to know how much power you car can produce. It's always possible to upgrade power and ground cables but for a hybrid maybe it's called a big 4 or a big 69... who knows?

 

[WJHybrid]

Well if you got from 12.5 to 13.5 it's an improvement. You can't go crazy with amps and subs without an alt. Try to know how much power you car can produce. It's always possible to upgrade power and ground cables but for a hybrid maybe it's called a big 4 or a big 69... who knows?

Well, the DC-DC Converter pretty much assumes the role of an alternator. It draws its power from the very large Hybrid battery, and can recharge the battery even when the engine is not running. The biggest difference in the 12v system for my hybrid as compared to a non-hybrid is the DC Converter in place of the Alternator. The 12v system is separate from the Hybrid system. I was more looking for information specifically pertaining to upgrading the electrical system of the Hybrid.

 

[gckless 5,000+ posts]

That's a tough one, and hopefully someone will have experience with Hybrids. The point of a DC-DC converter is to convert voltage levels, so I would wonder what the starting voltage is?

Another possible option would be to contact one of the HO alternator manufacturers (mechman, DC Power, Singer, etc.) and see if they have any info. See if it's possible to add an alternator on the engine, and then run that straight to some batteries in the back. That engine compartment looks pretty stuffed though. This would be a much more costly option though.

Or, just get a big bank of batteries?

This would be for the future, when you upgrade. Seeing voltages only hitting 13.5V isn't that bad, some people would love to see voltages that high lol. For what you are running now, you are fine.

 

[WJHybrid]

That's a tough one, and hopefully someone will have experience with Hybrids. The point of a DC-DC converter is to convert voltage levels, so I would wonder what the starting voltage is?
Another possible option would be to contact one of the HO alternator manufacturers (mechman, DC Power, Singer, etc.) and see if they have any info. See if it's possible to add an alternator on the engine, and then run that straight to some batteries in the back. That engine compartment looks pretty stuffed though. This would be a much more costly option though.

Or, just get a big bank of batteries?

This would be for the future, when you upgrade. Seeing voltages only hitting 13.5V isn't that bad, some people would love to see voltages that high lol. For what you are running now, you are fine.

Thanks for the reply. According to my manual, the DC-DC Converter is called a 42V DC-DC Converter. I can't find any info on what kind of amps it puts out, but did find a 120A fuse under my hood. Adding an alternator would be an interesting option. The bank of batteries may be extremely doable as well, as I have plenty of space where my spare tire used to be located. But would adding more batteries be ok without adding more output from my DC Converter?

So if 13.5V is good, how low can the voltage go before I would seriously need to do something? Thanks for the help.

 

[gckless 5,000+ posts]

Thanks for the reply. According to my manual, the DC-DC Converter is called a 42V DC-DC Converter. I can't find any info on what kind of amps it puts out, but did find a 120A fuse under my hood. Adding an alternator would be an interesting option. The bank of batteries may be extremely doable as well, as I have plenty of space where my spare tire used to be located. But would adding more batteries be ok without adding more output from my DC Converter?
So if 13.5V is good, how low can the voltage go before I would seriously need to do something? Thanks for the help.

So it probably steps up/down voltage to and from the 42V batteries to the 12V system, I'd assume?

Ideally you will want a bigger alternator, or in your case, an alternator period, since I don't think you will be able to increase the output from the Hybrid battery. In your vehicle electricity is provided by the batteries, where in a regular vehicle it is the alternator. Though I don't understand how the engine creates DC power to charge the batteries without an alternator. That's something you will want to look into. Anyway, since that isn't an option, your other option is to build a big reserve of electricity with batteries. Two issues with this: first, depending on what you will be drawing, you won't be able to listen to your system at full tilt for a long time. Since you will be drawing more than you are producing, your charging system (normally alternator, in your case that hybrid battery) will not be able to keep up, so your voltage will continually fall while you are in that electricity debt. Second, you will be around 12.6V (the resting voltage of your batteries, where your batteries start to provide power), so you won't be getting full power from those amps. You won't want to be less than 12V ever really, though personally I get nervous when I see under 13V when my car is running. That's probably my own personal paranoia from toasting an amp though :/

It will also be prudent to have a pretty good understand of how your electrical system works on that vehicle. That's a big battery under there, and I would really hate to see the aftermath if that thing were to overheat or destruct in some way. They probably have safeguards against that, but you never know. I'd visit some shops, email some people, find out everything you could.

 

[WJHybrid]

So it probably steps up/down voltage to and from the 42V batteries to the 12V system, I'd assume?
Ideally you will want a bigger alternator, or in your case, an alternator period, since I don't think you will be able to increase the output from the Hybrid battery. In your vehicle electricity is provided by the batteries, where in a regular vehicle it is the alternator. Though I don't understand how the engine creates DC power to charge the batteries without an alternator. That's something you will want to look into. Anyway, since that isn't an option, your other option is to build a big reserve of electricity with batteries. Two issues with this: first, depending on what you will be drawing, you won't be able to listen to your system at full tilt for a long time. Since you will be drawing more than you are producing, your charging system (normally alternator, in your case that hybrid battery) will not be able to keep up, so your voltage will continually fall while you are in that electricity debt. Second, you will be around 12.6V (the resting voltage of your batteries, where your batteries start to provide power), so you won't be getting full power from those amps. You won't want to be less than 12V ever really, though personally I get nervous when I see under 13V when my car is running. That's probably my own personal paranoia from toasting an amp though :/

It will also be prudent to have a pretty good understand of how your electrical system works on that vehicle. That's a big battery under there, and I would really hate to see the aftermath if that thing were to overheat or destruct in some way. They probably have safeguards against that, but you never know. I'd visit some shops, email some people, find out everything you could.

Well, from as much as I can gather from the manual and research, the vehicle has a traction motor that also serves as a generator of electricity when the engine is on. It recharges the hybrid battery, and the hybrid battery also gets recharged from regenerative braking. Engine doesn't create DC at all, it sends power to the Hybrid battery bank, and then the DC-DC Converter takes power from the bank, and sends it to the 12v. Here is a quote from the manual regarding the voltage of the Hybrid battery -

"The Hybrid System uses high voltage up to 650 V."

Not sure as to the validity of it, but I was told by one person at a reputable online audio place that my Hybrid system has a much larger potential for power, due to the amount of power it naturally stores. I suppose it would make sense though, because the 12v system does recharge itself by receiving power from the DC Converter, which gets its power from the Hybrid system.

The electricity bank idea is extremely doable, as I would be looking for a solution that would allow me to run my system at full tilt for like 20 minutes max. Rest of the time, it'd be listened to far below that power consumption. I agree about not wanting to go below 13V, higher I can keep the voltage, the better for everything.

No worries about the Hybrid seeing any overheat or destruct, as it has built in temp monitoring. If it reaches a certain temperature, it will shut the entire system down to protect itself.

I only bought this car because I got a major deal on it, picked up the hybrid version of the altima for 1k less than what the non-hybrid was going for. However, I am kind of regretting it now, as with a regular old engine vehicle, upgrading the electrical is straight forward.